Device for driving a film in a multifilm cinematographic projector



June 17, 1952 J. THEVENAZ 2,601,181

DEVICE FOR DRIVING A FILM IN A MULTIFILM CINEMATOGRAPHIC PROJECTOR Filed June 21, 1950 IN VENTOR ATTORNEY Jean Theve naz.

Patented June 17, 1952 DEVICE FOR DRIVING A FILM IN A MULTL- FILM CINEMATOGRAPHIC PROJECTOR Jean Thvenaz, Yvcrdon, Switzerland, assignor to Paillard S. A., a corporation of Switzerland Application June 21, 1950, Serial No. 169,365 In Switzerland June 30, 1949 2 Claims.

Known multifilm cinematographic projectors are in general only modified monofilm pr0jectors. However there are certain advantages in constructing a multifilm projector particularly one having an optical system for each film. This arrangement permits of having an optical system and a cam-claw system particularly adapted for each size. Further, as the feed members are secured to two ends of common driving shafts, the loading of the films as also the change from one size to another are operations which are both easy and rapid.

But this type of projector naturally results in new problems, in particular that of the control of two independent claws.

The present invention has for its object a device for driving a film in a multifilm cinematographic projector provided with at least two control cams secured to the same driving shaft, each of the cams being located in a plane par allel to that of the film and actuating an independent claw.

One form of construction of the subject of the invention is shown by way of example in the accompanying drawings, wherein:

Fig. 1 is a front elevation.

Fig. 2 is a plan view.

In the drawing 1 indicates the side walls of the projector which is provided on each of its two sides with an optical system suitable for the projection of a film of a different size for each optical system. In the example shown, the position of the window 2 on the left for projection of a 16 mm. film and window 3 on the right for projection of an 8 mm. film are indicated in broken lines.

The driving device for the two films of different sizes passing on front of the two said optical systems is the following: a driving shaft 4 located in the central plane between the walls I carries on the one hand a shutter 5, common to the two optical systems, and two cams 6 and I located in a plane parallel to that of the film.

The feed mechanism for the 16 mm. film is constituted by a lever 8 having at its end a claw 3 and pivoting about a pivot 16. The lever 8. by means of a shoe H, bears against the cam 5. A blade spring 12 bears against the bend end i3 of the lever 8 in such a manner as to hold the latter always in contact with the cam 6.

The cam 6 imparts to the lever 8 and to the claw 9 a downward movement when the claw 9 engages with a perforation of the film, then an ascending movement when the claw is disengaged from the film. The movement of penetration and disengagement of the claw 9 into and from the film is produced by the lateral face 13 of a third cam l4 mounted on the shaft 4 and which bears against the lever 8, the latter operating as a spring blade.

The feed mechanism for the 8 mm. film is similar to the preceding one. A lever 15 having at its end a claw l5, pivots about a pivot IT. A spring blade 18 bears against the bend end IQ of the lever l5 in such a manner as to maintain contact between a shoe 2!] of the said lever and the cam l.

The cam 1 produces the downward and upward movement of the lever 15, and therefore of the claw IE. Further the face 22 of the cam 6 bears against the lever l5 which operates like a blade spring thus producing the movement of penetration and disengagement of the claw l6 into and from the perforations of the film.

The two projection windows 2 and 3 may naturally be juxtaposed, in which case the two claws 9 and [6 are located on the same side of the driving shaft of the cams.

I claim:

1. In a multifilm cinema projector, the combination, comprising, a frame, a pair of levers each fulcrumed on the frame and resiliently bendable in the direction of the fulcrum axis, a claw at the end of each lever adapted to enter the perforation of a film, a rotatable shaft, a first pair of cams each constituted by the periphery of a disc and rigid with the shaft and each engaging one edge of a related lever to swing the same about its fulcrum, a second pair of cams each engaging an adjacent side of a related lever and bending same to move its claw thereof substantially parallel to the lever fulcrum, one of the second pair of cams constituted by the lateral face of one of the discs and the second one of the second pair of cams constituted by the lateral face of a third disc, and a pair of springs reacting against the frame and each urging a lever against one of the first pair of cams.

2. In a multifilm cinema projector. the com- 3 4 bination, comprising, a frame, a pair of levers the second one of said second pair of cams coneach fulcrumed at one end to the frame and stituted by the lateral face of a third disc resiliently bendable in the direction of the ful- JEAN TI-IEVENAZ.

crurn axis, a claw at the end of each lever opposite its fulcrum, a rotatable shaft arranged be- REFERENCES CITED tween the fulcrum and the claw of The following references are of record in the each lever, a first pair of cams each constituted file of this patent:

by the periphery of a disc rigid with the shaft and each engaging one edge of a related lever UNITED STATES PATENTS to swing the same about its fulcrum, a second 1:, Number Name Date pair of cams on said shaft each engaging an 2,484,348 Kellogg Oct. 11, 1949 adjacent side of a related lever and bending 2,521,957 'Wittel 'Sept.'12, 1950 same to 'move its claw thereof substantially parr. m allel to the lever fulcrum, one of said second DOREIGN PATENS pair of cams constituted by the lateral face of 5 Number Country Date one of the discs of said first pair of cams and 6781243 France "Dec-23,1929 

